1. Field of the Invention
This invention relates to electronic circuits and, more particularly, to electronic circuits that are used to detect digital data that appears on a parallel data bus.
2. Description of the Prior Art
We perceive a variety of characteristics of the things around us, such as colors, shapes, sizes, etc. These senses have been refined and extended by instruments, such as telescopes, microscopes, etc. Other instruments, such as magnetometers, have been developed in which there is no physiological sense developed in human beings.
Systems controlled by computers are now being used on the factory floor to run machine tools, track the contents of a warehouse, test products and monitor various industrial processes. Sensors contained within the foregoing systems are used to obtain information pertaining to the physical and chemical parameters of the goods being manufactured or produced so that human operators may adjust various instruments to control the quality of what is being produced. The information sensed by the sensors is encoded in the form of electrical signals that can be readily sorted, calculated, processed, converted, decoded and finally displayed on readout devices. Most systems provide for automatic repetitive measurements of the phenomena being sensed. The sensed information is sampled at some predetermined rate before the information is displayed on the readout devices. In order to process and display the desired information, it is necessary to use large computers and control electronics.